hemv¶
Computes a matrix-vector product using a Hermitian matrix.
Description¶
The hemv
routines compute a scalar-matrix-vector product and add the result to a scalar-vector product, with a Hermitian matrix. The operation is defined as
where:
alpha
andbeta
are scalars,A
is ann
-by-n
Hermitian matrix,x
andy
are vectors of lengthn
.
API¶
Syntax¶
void hemv(queue &exec_queue,
uplo upper_lower,
std::int64_t n,
T alpha,
buffer<T,1> &a,
std::int64_t lda,
buffer<T,1> &x,
std::int64_t incx,
T beta,
buffer<T,1> &y,
std::int64_t incy)
hemv
supports the following precisions and devices.
T |
Devices Supported |
---|---|
|
Host, CPU, and GPU |
|
Host, CPU, and GPU |
Input Parameters¶
- exec_queue
The queue where the routine should be executed.
- upper_lower
Specifies whether A is upper or lower triangular. See Data Types for more details.
- n
Number of rows and columns of
A
. Must be at least zero.- alpha
Scaling factor for the matrix-vector product.
- a
Buffer holding input matrix
A
. Must have size at leastlda
*n
. See Matrix Storage for more details.- lda
Leading dimension of matrix
A
. Must be at leastn
, and positive.- x
Buffer holding input vector
x
. The buffer must be of size at least (1 + (n
- 1)*abs(incx
)). See Matrix Storage for more details.- incx
Stride of vector
x
.- beta
Scaling factor for vector
y
.- y
Buffer holding input/output vector
y
. The buffer must be of size at least (1 + (n
- 1)*abs(incy
)). See Matrix Storage for more details.- incy
Stride of vector
y
.
Output Parameters¶
- y
Buffer holding the updated vector
y
.